• Journal of the Korean Society of Marine Environment & Safety
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• v.5 no.2
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• pp.27-33
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• 1999

The present study is concerned with the hydrostatic extrusion process of copper-clad aluminum rod through metallurgical joining. In this study, the rigid plastic finite element program, HICKORY, is used to analyze the steady state extrusion process of the bimetal rod. Simulations are performed for copper-clad aluminum rod with several extrusion ratio to give the distributions of effective strain rate, equivalent stress and hardness. Experiments are also carried out for aluminum-inserted copper rod at room temperature. It is found out that finite element predictions are generally in good agreement with the experimental observations. The detail comparison of the extrusion loads by the finite element method with those by experiments are given.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.03a
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• pp.140-143
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• 1997

The present study is concerned with the hydrostatic extrusion process of copper-clad aluminium bar to investigate the basic flow characteristics. Considering the bonding mechanism of bi-metal contact surface as cold pressure welding, the normal pressure and the contact surface expansion are selected as process parameters governing the bonding condition. The critical pressure required for the bonding at the interface is obtained by solving a "local extrusion" using a slip line meyhod. A viscoplastic finite element method is used to analyze the steady state extrusion process. The boundary profile of bi-metal rod is predicted by tracking a particle path adjacent to interface surface. The variations of contact surface area and the normal pressure along the interface profile are predicted and compared to those by experiments.

• Transactions of Materials Processing
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• v.7 no.1
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• pp.66-71
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• 1998

The present study is concerned with the hydrostatic extrusion process of copper-clad aluminium bar to investigate the bonding conditions as well as the basic flow characteristics. Considering the bonding mechanism of bi-metal contact surface as cold pressure welding the normal pressure and the contact surface expansion are selected as process parameters governing the bonding conditions, in this study the critical normal pressure required for the local extrusion-the protrusion of virgin surfaces by the surface expansion at the interface-is obtained using a slip line method and is then used as a criteron for the bonding. A rigid plastic finite element method is used to analyze the steady state extrusion process. The interface profile of bi-metal rod is predicted by tracking the paths of two particles adja-process. The interface profile of bi-metal rod is predicted by tracking the paths of two particles adja-cent to interface surface. The contact surface area ration and the normal pressure along the interface are calculated and compared to the critical normal pressure to check bonding. It is found that the model predictions are generally in good agreement with the experimental observations. The compar-isons of the extrusion pressure and interface profile by the finite element with those by experi-ments are also given.